1. Field of the Invention
This invention relates generally to aircraft devices, and more particularly, to an improved device for locking the ailerons and elevators of an aircraft so as to prevent unauthorized flight of a parked plane and also, for preventing theft of instruments or equipment from the instrument panel.
It is common knowledge that most light aircraft, for private use, are provided with cable operated controls including ailerons and elevators connected to a column, or shaft, turned by a wheel or yoke. The elevators during flight being positioned by pushing forward or pulling back the column in its longitudinal direction, and the ailerons being positioned by rotating the wheel.
Often such aircraft are not hangared, but merely tied down outside in a remote location on an airfield when not in use, so as to be subject to theft not only of the aircraft instruments, but also the aircraft itself. In general, the navigational instruments and radio equipment are constructed so that they can be readily installed or removed for repair or replacement from the front of the instrument panel. Accordingly, the removal and theft of the instruments and often the theft of the entire aircraft by flight from its parked position have become important concerns to the owners of such small aircraft.
2. Description of the Prior Art
A number of devices have been patented which are directed toward overcoming the problems briefly outlined above. Among these, U.S. Pat. No. 3,699,787 issued to Ronald F. Corrado, discloses a hollow cover which is mounted over a control column and directly in front of the instrument panel. The cover is locked in place by a tumbler lock which cooperates with a locking device fixed in the instrument panel. While this patent offers protection against theft of the instruments, it does not prevent a thief from manipulating the control shaft and connected wheel to fly the airplane away.
The Russel S. Ludeman U.S. Pat. No. 3,898,823, discloses a device for locking the controls of an aircraft which includes brackets secured to the pedals and wheel and connected by a tubular housing enclosing a piston-like spring device which resiliently locks the wheel and control column against movement when parked, so as to prevent unauthorized flights of the aircraft. It does not, however, offer any means to cover and prevent theft of the instruments from the instrument panel.
The Yates application mentioned above, offers a cover plate which mounts immediately adjacent the instrument panel and clamps about the aileron and elevator control column, thus providing a single device which both locks the aircraft controls and prevents theft of the aircraft instruments.